Gaseous fuel burner for producing radiant heat



May 11, 1965 J. 5. ZINK ETAL GASEOUS FUEL BURNER FOR PRODUCING RADIANTHEAT Filed Nov. 5, 1962 z Sheets-Sheet 1 JOHN SMITH ZI/VK ROBERT D. REEDy 1965 J. 5. ZINK ETAL 3,182,712

GASEOUS FUEL BURNER FOR PRODUCING RADIANT HEAT Filed Nov. 5, 1962 2Sheets-Sheet 2 INVENTORS JOHN SM/T H Zl/VK I? am 0. REED F/ 6. 5 BYZarronwer United States Patent 3,182,712 GASEGUSFUEL BURNER FORPRGDUCING RADIANT HEAT John Smith Zink and Robert D. Reed, Tulsa, Okla,assignors to .lohn Zink Company, Tulsa, Okla, 21 corporation of DelawareFiled Nov. 5, 1962, Ser. No. 235,439 3 Claims. (Cl. 158-116) The presentinvention relates to a burner for gaseous fuel and more specificallypertains to a burner assembly for discharging gaseous fuel over the faceof a ceramic member to provide a high temperature source of radiant heatdispersed over a relatively large area of the face of the Wall of afurnace or a chamber to be fired. This application is acontinuation-in-part of our application Serial No. 59,972, filedOctober- 3, 1960, now abandoned.

' It is known to provide for the discharge of a gaseous fuel from aplurality of discharge ports in directions which are parallel to theface of a refractory member to distribute the heat provided'by theburning fuel of over a substantial area of the ceramic member and such aburner assembly is disclosed in the Zink and Reed Patent 2,667,-

- 216. In the prior assembly ribs on the ceramic member intercept theflow of the gaseous fuel discharged from the burner head and .onepurpose of the ribs is to slow down the movement of the gaseous .fuelafter it escapes from the discharge ports in order to obtain stablecombustion. The present invention pertions to a fuel burner assemblydevoid of means for obstructing movement of the gaseous fuel after it isdischarged from the burner head and stable combustion is attained by theshape and disposition of the'discharge ports which are in the form ofelongated slots so that the gaseous fuel after escaping from the burnerhead loses velocity rapidly to provide for stable combustion and theslots are so disposed in relation to each other that there isco-mingling of the gas streams in areas closely adjacent the exit endsof the discharge ports to further promote stable burning.

An object of the invention is to provide a gas burner assembly whereinthe gaseous fuel is discharged through a multitude of slots which areelongated in the direction of the axis of the burner head and sodisposed as to provide for the discharge of one quantity of the gaseousfuel through one portion of each slot with respect to the quantity ofthe gaseous fuel escaping through another portion of each slot and toprovide a burner head wherein the discharge slots are arranged toprovide for changes in the directions at which gaseous fuel flows fromthe burner head in proceeding along the length of each slot.

Another object of the invention is to provide a burner head for gaseousfuel with a plurality of slots which are of elongated character measureddownstream of the burner head and which are formed in an outwardlybulged wall so that the gaseous fuel which moves in a path which isnormal to the surface from which it is discharged provides for thedispersion of the gaseous fuel escaping through the discharge slots infan like patterns over the face of a refractory member.

A still further object of the invention is to provide a burner head withrelatively narrow slots of elongated shape and in such a large number asto provide a large total discharge area for the fuel mixture and toprovide slots of such structure as to prevent flashback from thecombustion zone into the burner headeven when the gaseous fuel containsappreciable quantities of rapidly reacting gaseous fuels in astoichiometric mixture with air. 1

Another object of the invention is to provide an up stream surface aonthe burner head to develop radially outward components togthe gaseousfuel mixtureafter.

3,182,712 Patented May 11, 1965 it engages the upstream surface of theburner head to develop scrubbing of the associated portions of theburner head with the incoming cooling gaseous fuel to thereby preventoverheating of the downstream portions of the burner head.

A further object of the invention is to provide structure on the burnerin the vicinity of the upstream ends of the discharge slots to promote asteady flow of the gaseous fuel through the ports adjacent the upstreamends.

Other objects and features of the invention will be appreciated by thoseskilled in the art pertaining to the combustion of gaseous fuels and asthe present disclosure proceeds and upon consideration of the followingdetailed description taken in conjunction with the accompanying drawingswherein exemplary embodiments of the invention are disclosed.

In the drawings: 7 FIG. 1 is a plan view of a burner head exhibiting theinvention shown in association with a ceramic member and a portion ofthe wall of a combustion chamber.

FIG. 2 is an enlarged sectional view taken on the line 2-2 of FIG. 1.

FIG. 3 is a sectional view of the burner head taken on the line 3-3 ofFIG. 2 and showing a portion of the ceramic burner block.

FIG. 4 is a sectional view of a modified burner head taken on the line4--4 of FIG. 5. a

FIG. 5 is a plan view of the burner head shown in FIG. 4 with a portionillustrated in section and taken on, the line 55 of FIG. 4.

The'invention pertains to a burner for discharging a gaseous fuelmixture in a substantially annular pattern about the burner head andalong the face of a ceramic member to provide a relatively large area ofradiant heat over the wall of a furnace chamber. A portion of a fire boxwall 11 formed of refractory material is shown in FIG. 1 and this mayconstitute the floor of a chamber which is to be fired. A burner block11 formed of suitable ceramic material desirably provides a part of thewall or floor of the furnace chamber. The block 11 may be of rectangularshape as shown in FIG. 1 and provided with a fiat face 12 (FIG. 2)mounted flush with the inner face of the refractory wall.

The burner block 11 is provided with a cylindrical shaped opening 14 foraccommodating a portion of the burner head 16. The burner head formed ofmetal has a diameter which is slightly less than that of the opening 14.The downstream end of the burner head 16 is closed by a disc shaped wall17 and it has a conical shaped upstream face 18. The apex 19 of theupstream face. is directed upstream of the burner and coincides with theaxis of the burner head.

A conduit 21 forms a part of the burner head and provides means forguiding a gaseous fuel mixture towards the face 18 of the Wall 17 in thedirection of the arrows 22. An annular wall 23 joins the downstream endof the conduit 21 with the perimeter of the discshaped wall 17. Thediameter of the conduit 21 is smaller thanthat of the disc-shaped wall17 but the wall 23 desirably has an arcuate or spherical shape andbulges outwardly as shown in FIG. 2. The burner is maintained in acentered position with respect to the opening 14 in the burner block bymeans of circumferentially spaced lugs 24 extending radially from theperimeter of the conduit 21.

g A unique feature of the burner head pertains to the shape anddisposition of the discharge ports for the escape of the gaseousfuelmixture from the chamber 28 provided between the wall 17 and theannular bulged wall 23; The discharge ports are in the form of elongatedslots 26. A multitude of slots 26 are provided in the wall 22 and in theembodiment illustrated there are more than forty of such slots spacedfrom each other around the circumference of the burner head. Each slot26 extends from the downstream end portion of the conduit 21 to theupstream face 18 of the end wall 17. These elongated discharge slots 26may be formed in any suitable manner and in one embodiment each slot 26has a width of approximately 0.0 r inch. Each slot is long in relationto its width and in a typical embodiment each slot has a length ofapproximately one and one-half inches. Each discharge slot 26 may havean area of approximately 0.06 square inch. The wall 23 is relativelythick and may be secured to the conduit 21 by weldingas indicated at 27.

A supply of gas with air inspirated thereinto and mixed therewith involume equal to or greater than theoretical is supplied under pressureinto the conduit 21. The fuel mixture moves in the direction of thearrows 22 and encounters the face 18 of the wall 17. Pressure is thusbuilt up adjacent the face 18 and the zone of highest pressure withinthe chamber 28 is indicated at A in FIG. 2. The pressures at B, C, D andE are progressively lower. If the pressure Within the burner headadjacent the zone E is but a few hundredths of an inch of water greaterthan the pressure externally of the burner head the pressure in the zoneA is greater than one inch of water. The volume of the flow of thegaseous fuel mixture outwardly through any one of the discharge slots 26varies with the square root of the pressure applied at the portal of theslot. Thus when the pressure in the zone A amounts to one inch of waterand the pressure in the zone B is 0.10 inch of water the flow of thegaseous fuel through the zone A of each slot 26 will be 3.16 timesgreater than the flow through the portion E of each slot 26. Thevelocity of the discharge of the gaseous fuel mixture varies at the sameratio.

A relationship of velocities and pressures as hereinabove described,provides the advantageous result of dispersing the burning gaseous fuelover the face 12 of the ceramic block 11. The discharge of the fuel isin an annular pattern so that the dispersion of the burning gaseous fuelis over a large annular area of the block 11 and the wall and such apattern is provided by the varying pressures at which the fuelisdischarged. from the zones A to D. The flow from the zone B isrelatively small in relation to the volume of fuel discharged throughother portions of each slot 26. The relatively small volume of fuelmixture escaping in the zone B is influenced by the gaseous fuelescaping through that portion of each slot 26 downstream of the zone Bso that the higher velocities in the zones D to A pull the fuel mixtureescaping through the zone E forwardly to cause the fuel mixture escapingin the zone E to move outwardly along the downstream face 12 of therefractory block. a The arrows 31 associated with the zones A to D inFIG. 2 indicate the approximate direction of the flow of the gaseousfuel in the respective zones. It will be observed that the outwardmovement of the gaseous fuel as represented by the arrows 31 is in onegeneral direction with portions of the fuel moving at slightly differentdirections but all of the escaping fuel converges upon the face 12 ofthe ceramic block. The gaseous fuel mixture escaping through each slot26'tends to flow normal to the surface from which it is discharged andas a consequence of the arcuate. character of the outer surface of thewall 23 the fuel escaping through each slot 26 has a fan shape and isdirected towards the facelZ of the ceramic block.

The ceramic body 11 is accordingly heated to provide a source of radiantheat and the burning fuel mixture is dispersed over a large area of theface 12. A high temperature is' developed over an annular area aroundthe burner head and the high temperature is not confined to the zoneimmediately adjacent the burner head. The area of the face 12 may varyand the ceramic block 11 is d heated and adjacent portions of the wall19 are also heated as a result of the gaseous fuel escaping from thezone A and some of the gaseous fuel mixture discharged in the zone B.The heat need not be confined to the block 11 and there may be someheating of the face of the wall 10.

The deceleration of the gas escaping through the slot 26 is such that itis not necessary to provide means obstructing the outward flow of themass of gas. Stable burning is attained by the close proximity of theslots 26 to each other and in one embodiment they are spaced on onequarter inch centers. The fuel mixture escaping through the exit ends ofthe slots 26 co-mingle close to the exterior of the wall 23 and anignition temperature is developed close to the perimeter of the burnerhead. The co-mingling of the fuel immediately after passing the exitends of the slots 26 is a consequence of the low pressure in theadjacent streams while there is a normal pressure out-side the wallintermediate the slots 26. The action of co-mingling of the gaseous fueland the quick ignition of the fuel develops an extraordinarily hightemperature close to the perimeter of the burner head so that the flowas it is directed towards the ceramic block 11 causes the temperaturethereof to rise to high levels in the annular area surrounding theburner head. The high temperature of the refractory material enhancesthe condition of radiant heat density immediately downstream of therefractory member.

The wall 23 is thick so that the length of the passage through each slot26 in the direction of the arrows 31 is long in relation to the area ofthe discharge ports. It is this relationship which serves to preventflashback from the combustion zone into the chamber 28. The length ofthe discharge passages measured in the direction of the arrows 31 issuch as there is cooling action by the flow of the gaseous fuel mixturetherethrough so that the burner head operate-s satisfactorily even whenthe fuel is a mixture of air with hydrogen, acetylene or ethylenebecause the flow passages are long enough to'produce the cooling efiFectrequired for these extremely actively chemically gases.

A modified head is shown in FIGS. 4 and 5 wherein the end wall 17a isprovided with a conical surface 18a which is disposed at a smaller anglewith respect to the axis of the burner head. The apex 19a of the conicalsurface is directed upstream of the burner head and is substantiallyaligned with the axis of the burner. The conical surface 18 and theconical surface 18a serve to deflect the gaseous fuel mixture radiallyoutward from the axis of the burner head. The conical surface 18a may bedisposed at an angle of approximately forty degrees with respect to theaxis of the conduit 21 so as to effectively deflect the gaseous fuelradially outward and avoid any tendency of eddy currents being developedalong the upstream surface of the end wall. The conical surface 18a issubjected to scrubbing by the cool gaseous fuel mixture wherebyoverheating of the end wall of the burner head is avoided. Thedownwstream portion of the burner head shown in FIGS. 4 and 5 operatesat a temperature which is significantly lower than the operatingtemperature of the burner head shown in FIG. 1.

The burner head shown in FIGS. 4 and 5 includes a generally cylindricalshaped conduit portion 4-1 which may be welded to the conduit 21 asindicated at 27. The conduit portion or sleeve 41 has an outwardlyflared annular surface 42 which merges smoothly with the inner surfaceof the bulged wall 23 so that the gaseous fuel mixture flows smoothlythereover and avoids the possibility of eddy currents being developed atthe upstream ends of the discharge slots 26.

While the invention has been described with reference to specificstructural characteristics and with regard to one burner head and aceramic body it will be appreciated that changes may be made in thevarious elements as well as alteration in the overall assembly. ,Suchmodifications and others may be made without departing from the spiritand scope of the invention as set forth in the appended claims.

What We claim and desire to secure by Letters Patent is: 1. A burnerassembly for gaseous fuel comprising, ceramic means having a flat facethroughout and in a single plane confronting a space to be fired, saidceramic means 7 under pressure from said conduit, said annular wallhaving a spherical shaped outer surface and having a plurality ofelongated slots therein all extending in the direction of the axis ofthe burner head, said annular wall having a thickness ,of such magnitudewith relation to the width of said slots as to prevent backfla'sh,upstream ends of said slots being positioned adjacent the face of saidceramic means and downstream of said face, and the downstream ends ofsaid slots terminating adjacent the upstream face of said end wall.

2. A burner assembly for gaseous fuel comprising, ceramic means having aflat face in a single plane confronting a chamber to be fired, saidceramic means having an opening therethrough, a conduit of smaller crosssection than said opening arranged therein, an end wallarrangedtransversely of and spaced from the downstream end of said conduit, theperimeter of said end wall projecting beyond the perimeter of saidconduit, an annular wall joining the perimeter of said end Wall with thedownstream end of said conduit providing a burner head with a chambertherewithin for receiving gaseous fuel under pressure from saidconduit,said annular wall having a convex shaped outer surface arching from saidend Wall to said conduit, said annular wall having a plurality ofelongated slots therein all extending in the direction of the axis ofthe burner head, a conical surface on said end Wall having its apexdirected upstream of said burner head, said annular Wall having athickness of such magnitude with relation to the Width of said slots asto prevent backfiash, up-

. stream ends of said slots being positioned adjacent the face of saidceramic means and downstream of said face, the downstream ends of saidslots terminating adjacent the upstream face of said end wall, and saidelongated slots being disposed adjacent each other measuredcircumferentially of said annular wall whereby the gaseous fuel escapingthrough the slots co-mingle close to the exterior of said annular Wall.

3. A burner assembly for gaseous fuel according to claim 2, wherein theapex of the conical surface is substantially in alignment with the axisof the burner head and the conical surface has a slope of approximatelyforty degrees with respect to the axis of the burner head.

References Cited by the Examiner UNITED STATES PATENTS 103,297 5/70 Burt158116 X 194,561 8/77 Prentiss 158-68 1,393,547 10/21 Kotzebue 158-692,591,263 4/52 James et al. 158116 2,667,216 1/54 Zink et a1. 158-1132,806,465 9/57 Hess. 2,870,829 1/59 Williams.

FOREIGN PATENTS 3 86,223 4/08 France.

570,248 1/24 France.

142,759 5/20 Great Britain.

JAMES W. WESTHAVER, Primary Examiner.

FREDERICK L. MATTESON, JR., PERCY L. PAT- RICK, Examiners

1. A BURNER ASSEMBLY FOR GASEOUS FUEL COMPRISING, CERAMIC MEANS HAVING AFLAT FACE THROUGHOUT AND IN A SINGLE PLANE CONFRONTING A SPACE TO BEFIRED, SAID CERAMIC MEANS HAVING AN OPENING THERETHROUGH, A CONDUIT OFSMALLER CROSS SECTION THAN SAID OPENING ARRANGED THEREIN, AN END WALLARRANGED TRANSVERSELY OF AND SPACED FROM THE DOWNSTREAM END OF SAIDCONDUIT, THE PERIMETER OF SAID END WALL PROJECTING BEYOND THE PERIMETEROF SAID CONDUIT, AN ANNULAR WALL JOINING THE PERIMETER OF SAID END WALLWITH THE DOWNSTREAM END OF SAID CONDUIT PROVIDING A BURNER HEAD WITH ACHAMBER THEREWITHIN FOR RECEIVING GASEOUS FUEL UNDER PRESSURE FROM SAIDCONDUIT, SAID ANNULAR WALL HAVING A SPHERICAL SHAPED OUTER SURFACE ANDHAVING A PLURALITY OF ELONGATED SLOTS THEREIN ALL EXTENDING IN THEDIRECTION OF THE AXIS OF THE BURNER HEAD, SAID ANNULAR WALL HAVING ATHICKNESS OF SUCH MAGNITUDE WITH RELATION TO THE WIDTH OF SAID SLOTS ASTO PREVENT BACKFLASH, UPSTREAM ENDS OF SAID SLOTS BEING POSITIONEDADJACENT THE FACE OF SAID CERAMIC MEANS AND DOWNSTREAM OF SAID FACE, ANDTHE DOWNSTREAM ENDS OF SAID SLOTS TERMINATING ADJACENT THE UPSTREAM FACEOF SAID END WALL.